From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BE1FC4320A for ; Wed, 28 Jul 2021 08:17:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66FF660BD3 for ; Wed, 28 Jul 2021 08:17:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234646AbhG1IRI (ORCPT ); Wed, 28 Jul 2021 04:17:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48733 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234962AbhG1IRE (ORCPT ); Wed, 28 Jul 2021 04:17:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627460222; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YdfX05LskuF4LkLPQ7JXhLXY5W9XsKs2E3Vm5Szjjo0=; b=U3AtKSR3EDn4YwhpsUFysB6U6l+lHrbbNnBCs1VsgAcDmb1o7kybqDRoHmwO9A7s7nfzll btvO0uRGr1i/Zw4uQ1P3Jw0rGC0t1nS59K+9JCnAfFnP4WSktJQAHJ392RwuotyJVOiMUu 7Z7DeC9Q2DEJdiiOExd7HQY+Z27OQxE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-117-6uIouBW2PHOpc-u15TNomw-1; Wed, 28 Jul 2021 04:17:01 -0400 X-MC-Unique: 6uIouBW2PHOpc-u15TNomw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AF4771006C84; Wed, 28 Jul 2021 08:16:59 +0000 (UTC) Received: from localhost (ovpn-13-99.pek2.redhat.com [10.72.13.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF62A60C05; Wed, 28 Jul 2021 08:16:58 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , Dan Schatzberg , Ming Lei Subject: [PATCH V2 2/7] loop: clean up blkcg association Date: Wed, 28 Jul 2021 16:16:33 +0800 Message-Id: <20210728081638.1500953-3-ming.lei@redhat.com> In-Reply-To: <20210728081638.1500953-1-ming.lei@redhat.com> References: <20210728081638.1500953-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Each loop_worker is responsible for running requests originated from same blkcg, so: 1) associate with kthread in the entry of loop_process_work(), and disassociate in the end of this function, then we can avoid to do both for each request. 2) remove ->blkcg_css and ->memcg_css from 'loop_cmd' since both are per loop_worker. Also kill #ifdef in the related functions. Acked-by: Dan Schatzberg Signed-off-by: Ming Lei --- drivers/block/loop.c | 81 +++++++++++++++++++++++--------------------- drivers/block/loop.h | 2 -- 2 files changed, 43 insertions(+), 40 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index f37b9e3d833c..1756c17d3936 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -936,23 +936,46 @@ static inline int queue_on_root_worker(struct cgroup_subsys_state *css) { return !css || css == blkcg_root_css; } +static struct cgroup_subsys_state *loop_rq_blkcg_css(struct loop_cmd *cmd) +{ + struct request *rq = blk_mq_rq_from_pdu(cmd); + /* always use the first bio's css */ + struct blkcg *blkcg = bio_blkcg(rq->bio); + + if (blkcg) + return &blkcg->css; + return NULL; +} #else static inline int queue_on_root_worker(struct cgroup_subsys_state *css) { return !css; } +static struct cgroup_subsys_state *loop_rq_blkcg_css(struct loop_cmd *cmd) +{ + return NULL; +} #endif +static struct cgroup_subsys_state *loop_rq_get_memcg_css( + struct cgroup_subsys_state *blkcg_css) +{ + if (blkcg_css) + return memcg_get_e_css(blkcg_css->cgroup); + return NULL; +} + static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) { struct rb_node **node = &(lo->worker_tree.rb_node), *parent = NULL; struct loop_worker *cur_worker, *worker = NULL; struct work_struct *work; struct list_head *cmd_list; + struct cgroup_subsys_state *blkcg_css = loop_rq_blkcg_css(cmd); spin_lock_irq(&lo->lo_work_lock); - if (queue_on_root_worker(cmd->blkcg_css)) + if (queue_on_root_worker(blkcg_css)) goto queue_work; node = &lo->worker_tree.rb_node; @@ -960,10 +983,10 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) while (*node) { parent = *node; cur_worker = container_of(*node, struct loop_worker, rb_node); - if (cur_worker->blkcg_css == cmd->blkcg_css) { + if (cur_worker->blkcg_css == blkcg_css) { worker = cur_worker; break; - } else if ((long)cur_worker->blkcg_css < (long)cmd->blkcg_css) { + } else if ((long)cur_worker->blkcg_css < (long)blkcg_css) { node = &(*node)->rb_left; } else { node = &(*node)->rb_right; @@ -977,15 +1000,10 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) * In the event we cannot allocate a worker, just queue on the * rootcg worker and issue the I/O as the rootcg */ - if (!worker) { - cmd->blkcg_css = NULL; - if (cmd->memcg_css) - css_put(cmd->memcg_css); - cmd->memcg_css = NULL; + if (!worker) goto queue_work; - } - worker->blkcg_css = cmd->blkcg_css; + worker->blkcg_css = blkcg_css; css_get(worker->blkcg_css); INIT_WORK(&worker->work, loop_workfn); INIT_LIST_HEAD(&worker->cmd_list); @@ -2098,19 +2116,6 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, break; } - /* always use the first bio's css */ - cmd->blkcg_css = NULL; - cmd->memcg_css = NULL; -#ifdef CONFIG_BLK_CGROUP - if (rq->bio && rq->bio->bi_blkg) { - cmd->blkcg_css = &bio_blkcg(rq->bio)->css; -#ifdef CONFIG_MEMCG - cmd->memcg_css = - cgroup_get_e_css(cmd->blkcg_css->cgroup, - &memory_cgrp_subsys); -#endif - } -#endif loop_queue_work(lo, cmd); return BLK_STS_OK; @@ -2122,28 +2127,14 @@ static void loop_handle_cmd(struct loop_cmd *cmd) const bool write = op_is_write(req_op(rq)); struct loop_device *lo = rq->q->queuedata; int ret = 0; - struct mem_cgroup *old_memcg = NULL; if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { ret = -EIO; goto failed; } - if (cmd->blkcg_css) - kthread_associate_blkcg(cmd->blkcg_css); - if (cmd->memcg_css) - old_memcg = set_active_memcg( - mem_cgroup_from_css(cmd->memcg_css)); - ret = do_req_filebacked(lo, rq); - if (cmd->blkcg_css) - kthread_associate_blkcg(NULL); - - if (cmd->memcg_css) { - set_active_memcg(old_memcg); - css_put(cmd->memcg_css); - } failed: /* complete non-aio request */ if (!cmd->use_aio || ret) { @@ -2199,7 +2190,21 @@ static void loop_workfn(struct work_struct *work) { struct loop_worker *worker = container_of(work, struct loop_worker, work); - loop_process_work(worker, &worker->cmd_list, worker->lo); + struct mem_cgroup *old_memcg = NULL; + struct cgroup_subsys_state *memcg_css = NULL; + + kthread_associate_blkcg(worker->blkcg_css); + memcg_css = loop_rq_get_memcg_css(worker->blkcg_css); + if (memcg_css) { + old_memcg = set_active_memcg( + mem_cgroup_from_css(memcg_css)); + loop_process_work(worker, &worker->cmd_list, worker->lo); + set_active_memcg(old_memcg); + css_put(memcg_css); + } else { + loop_process_work(worker, &worker->cmd_list, worker->lo); + } + kthread_associate_blkcg(NULL); } static void loop_rootcg_workfn(struct work_struct *work) diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 1988899db63a..a52a3fd89457 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -77,8 +77,6 @@ struct loop_cmd { long ret; struct kiocb iocb; struct bio_vec *bvec; - struct cgroup_subsys_state *blkcg_css; - struct cgroup_subsys_state *memcg_css; }; /* Support for loadable transfer modules */ -- 2.31.1